3-3.5? Geez, what are you watering with, cola? They like acid, but not *that* acid. That's even on the acid side for rooibos!

If what we're seeing is nutrient deficiency (I can't guarantee that) - purple tones on leaf edges generally means phosphorus deficiency, while yellowing while the veins stay green, without browing at the tips/edges, is usually magnesium deficiency. Phosphorus deficiency can be due to soil pH being too high or too low, and magnesium deficiency often happens when soil pH is too low.

Might want to add dolomite and some superphosphate.

But again, there's lots of other things that can hurt plants, and right now I'm only thinking of nutrients

Douse that puppy with a few teaspoons of Epson salt. Get your pH to 5 - 5.5 for blueberry bushes. Wouldn't hurt to add some premium worm castings. Really nice mixes from boogie brew. Pull out of the West sun for now, and transfer to a fabric pot such as 247.

Can add Epsom salt. What's the reason for putting it in fabric pot and not providing more sun? Does plastic pot and more not good for blueberry?

Few reasons. First, the plant is ultra stressed and very young and needs to drop those dying leaves and push new growth--best done out of the West sun in a 9a zone as it currently cannot protect its canopy from sun scald and will suffer dieback. Morning eastern sun mixed with mixed sun/shade in the afternoon will help it recover quicker.

Next, fabric pots will prevent root binding and release some of the acidity from the soil while retaining some micros. Runner roots will hit the edge of fabric and cause it to send out some feeder roots rather than spinning around a plastic pot and binding the root ball. Also, plastic pots sitting in 9a sun will get too hot and cause dead zones within your potential root ball. Fabric pots don't overheat and breathe easily and are lightweight. I quit using plastic pots for nearly all of my plants as of a few years ago and am a wishing I had converted to fabric much sooner.

Plus you can order the things for dirt cheap directly from 247garden.com. Don't waste money on expensive smart pots--247 does the same thing at a fraction the cost and range from 1/4 g to 400g in size.

For my blueberries, I use a strict mix of 30/30/30/10 mix of perlite/peat moss/mini pine nuggets/coir. Don't be afraid to make your own soil and repot that blueberry to fix it's soil conditions--just keep it well watered for a couple of weeks if you do. Add some premium worm castings and Epsom salt to the new soil, and until it recovers, a light dosage of Osmocote slow release would be beneficial.

I'd also as mentioned use some superphosphate. Remedying the pH situation might fix the apparent phosphorus deficiency on its own, or it might not. Phosphorus is poorly mobile in soil and generally spends most of its time sequestered, so if you're repotting, that's the best time to add it. And if you're raising the pH, I'd (as mentioned) use dolomite or any other form of aglime that contains magnesium to do so. Two birds with one stone. If you add only calcium compounds to increase the pH, you risk worsening a magnesium deficiency, as magnesium and calcium compete in the roots.

I'd also as mentioned use some superphosphate. Remedying the pH situation might fix the apparent phosphorus deficiency on its own, or it might not. Phosphorus is poorly mobile in soil and generally spends most of its time sequestered, so if you're repotting, that's the best time to add it. And if you're raising the pH, I'd (as mentioned) use dolomite or any other form of aglime that contains magnesium to do so. Two birds with one stone. If you add only calcium compounds to increase the pH, you risk worsening a magnesium deficiency, as magnesium and calcium compete in the roots.

This is very good advice from Karen. Make sure when adding a superphosphate that you also bring up potassium and sulphur with it if testing deficient.. Only takes very small amounts.